Technical Field
The present disclosure relates to a light emitting device.
Discussion of the Background
Light emitting diodes (hereinafter abbreviated as “LEDs”) have been used as various light sources for a lighting device as well as an optical communication device from the viewpoints of their high light emitting efficiency, low power consumption, and long lifetime. In particular, a light emitting device having a plurality of light emitting elements arrayed on a substrate has been used in a printer, a scanner, or a composite machine including them.
In addition, a light emitting device for linearly emitting desired light such as ultraviolet light or visible light has been used in many fields of a scanner, ink, resin hardening, panel sticking, and the like.
The plurality of light emitting elements arrayed on a substrate have been used as a light source of ultraviolet light or visible light.
A light emitting element for use in the above-described light emitting device has a structure in which, for example, p-type and n-type semiconductor layers are epitaxially grown, and thereafter, p-electrodes and n-electrodes that include conductors are bonded to the corresponding semiconductor layers. In a light emitting element of a so-called vertical structure, an n-electrode (i.e., a cathode) is disposed on a light extracting surface side of the light emitting element whereas a p-electrode (i.e., an anode) is disposed on a reverse surface side opposite to the light extracting surface side. Die bonding is performed such that the p-electrode at the reverse surface of the light emitting element is bonded to a conductive pattern formed on the substrate via soldering or conductive paste. And then, the n-electrode on the light extracting surface side is subjected to wire bonding between a bonding region of the substrate and the same, so that the light emitting element and the substrate are electrically connected to each other.
As the above-described LED light emitting device having the plurality of light emitting elements arrayed on the substrate has been proposed, for example, an LED device including: a substrate having a first edge and a second edge that is faced to the first edge and parallel to the first edge, and a conductive pattern provided on an upper surface of the substrate, the conductive pattern having a first bonding area which lies on a first edge side of the substrate and a second bonding area which lies on a second edge side of the substrate; an LED chip having a first edge and a second edge that is faced to the first edge and parallel to the first edge, and having a first pad electrode which lies on a first edge side of the LED chip, and a second pad electrode which lies on a second edge side of the LED chip, the first and second pad electrodes being provided on two diagonal corners of an upper surface of the LED chip, the LED chip being mounted on the substrate so that the first edge of the LED chip and the first edge of the substrate become parallel to each other at intervals and the second edge of the LED chip and the second edge of the substrate become parallel to each other at intervals; a first wire installed between the first pad electrode and the first bonding area; and a second wire installed between the second electrode and the second bonding area; wherein an installing direction of the first wire from the first pad electrode, as viewed from thereabove, constitutes a direction which is inclined at 15 to 40 degrees towards an orientation which moves away from the first edge of the LED chip with respect to a moving-away direction that is orthogonal to the first edge of the LED chip and toward the first edge of the substrate from the first edge of the LED chip; and wherein an installing direction of the second wire from the second pad electrode, as viewed from thereabove, constitutes a direction which is inclined at 15 to 40 degrees towards an orientation which approaches the second edge of the LED chip with respect to a second orthogonal moving-away direction that is orthogonal to the second edge of the LED chip and toward the second edge of the substrate from the second edge of the LED chip. (Japanese Unexamined Patent Application Publication No. 2011-216514).